A number of work positioning devices have been previously described such as for example the positioners of U.S. Pat. Nos.: 2,898,068, 5,314,174, 5,738,344 and 5,544,968. The support of U.S. Pat. No. 2,898,068 describes a device having a split ball-bushing configuration and having a clamping screw that engages the bushing locking the positioning post in place. Unfortunately, the screw clamp requires active interaction with the user to both release the bushing enabling movement of the item secured in the device and lock the bushing once the desired position is achieved. Further, it requires the user to apply a sufficient amount of pressure with the screw clamp to assure that the item remains in position. Unfortunately, if enough pressure is not applied, the positioner can fail and the item held in the device can be damaged.
U.S. Pat. Nos. 5,314,174 and 5,738,344 describe a workpiece positioner having a ball in socket configuration with a fluid chamber for providing fluidic pressure to release the positioning arm, permitting the arm to rotate and tilt up to 45 degrees from vertical. Unfortunately, these devices cannot tilt an item secured in the positioner greater than 45 degrees. In addition fluidic pressure control systems rely on a number of components to operate optimally for the system to function properly including for example gaskets which have a finite optimal operation lifetime and must be replaced, fluid level which must be monitored regularly and pressure hoses and lines that must be maintained.
Another device described in U.S. Pat. No. 5,544,968 is a positioning platform using a ball in socket configuration and a clamp ring positioned around the ball. Fluidic pressure is supplied to activate the rotation of the platform about the ball. Unfortunately in this configuration the device cannot tilt an item secured to the platform greater than 45 degrees. In addition, as with the other devices discussed, fluidic control systems have a number of components that require constant care and monitoring.
Consequently, there is a need for a universal positioner that does not use split ball screw clamping or a ball in socket configuration that limits the tilting capability to less than 45 degrees from vertical.